1. Field of the Invention
The present invention relates to a volume adjusting method, and more particularly, to a volume adjusting method for channel switching of a digital television.
2. Description of the Prior Art
In families, a television may provide people with entertainments. For better entertainments, visual qualities and audio qualities of televisions are getting important, as well as interactions with the televisions. Digital televisions are designed for providing better visual qualities and audio qualities in entertainments, and therefore, visual and audio requirements of digital televisions are highly regulated as well.
A digital television is often switched to play programs of different channels, each of which uses different levels of remembered volumes, a receiver of the digital television, which may also be called as a digital television receiver and be implemented within a set top box, may record a used volume for each channel played by the digital television, where the recorded volume is used at a last time when the user switches the digital television to each the channel. Volumes of other portable devices, such as a portable television or a personal digital assistant capable of playing programs of various channels, may also be recorded according to the various channels received by the portable devices with the aid of similar receivers.
However, a same digital television may be used by different people so that the digital television has to follow different volumes in the volume setting for each the channel played by the digital television, and therefore, some defects may arise. For example, when a user of the digital television switches from a first channel, which uses a significantly low remembered volume, to a second channel, which uses a significantly high remembered volume, the user may be frightened by a huge volume difference from the significantly low remembered volume to the significantly high remembered volume.
In US Patent Application No. 20060018493, an apparatus and method is disclosed for compensating volume in response to a channel change. In the related disclosure, disclosed characteristics include generating a gain to adjust a level of an input audio signal by comparing an average level of the input audio signal with a predetermined input/output curve, adjusting a volume of the input audio signal by applying the generated gain to the level of the input audio signal, and adjusting a dynamic range of the audio signal having the adjusted volume. However, according to the disclosed application, when the new channel plays soft voices, which indicate a significantly low volume, or explosion of bombs, which indicate a significantly high volume, at the time when the user of the digital television switches to the new channel, the generated gain may be deviated from succeeding volumes of the new channel so as to bring unexpected peaks or foots in volume. Moreover, if the gain is adjusted continuously for matching the succeeding volumes of the new channel, played volumes of the digital television are not stable also as a price so that audio qualities of playing programs of the new channel are significantly reduced. As can be inducted, continuously adjusting the played volume of the new channel on the digital television may not be feasible because of the price of affecting the audio qualities of the digital television.